Blade sharpening apparatus



April 29, 1969 K. w. WRIGHT 3,440,772

BLADE SHARPENING APPARATUS Filed Aug. 29, 1966 Sheet Of 2 INVENTOR KENNETH W. WRIGHT ATTO RNEYS April 1969 K. w. WRIGHT 3,440,772

BLADE SHARPENING APPARATUS Filed Aug. 29, 1966 Sheet 2 of 2 FIGB INVENTOR 88 K NETH wwmw.

BY Wf ma $5 Z J ATTORNEYS United States Patent 3,440,772 BLADE SHARPENING APPARATUS Kenneth W. Wright, 3206 Cherokee St., Flint, Mich. 48507 Filed Aug. 29, 1966, Ser. No. 575,681 Int. Cl. B24b 23/04, 23/02 US. Cl. 51-170 Claims ABSTRACT OF THE DISCLOSURE This invention relates particularly to apparatus for finishing cutting devices such as barber clippers which normally comprise a pair of companion cutting sections having a common sliding bearing surface. Cutting devices of this type achieve their cutting action by a relative oscillating motion between the cutting sections so that the edges of teeth on one of the cutting sections meets the edges of teeth on the other companion cutting section. The efficiency of these type of cutting devices is dependent on the flatness and smoothness of the companion bearing surfaces. It is, therefore, essential that the bearing surface of each of the cutting sections is absolutely smooth and fiat.

conventionally, barber clippers and the like have been sharpened and resharpened bya hand grinding operation. Thus, the clipper blade section is manually held and reciprocated against a grinding stone. The problem associated with hand grinding is that a uniform grinding cannot normally be achieved on the bearing surface. Thus the edges of the teeth are often left with a rough finish that scratches the skin of the user or the surfaces are left with a lopsided finish thereby preventing a proper mating of the companion cutting sections.

It is the broad-purpose of the present invention to provide portable apparatus for automatically lapping a smooth and flat cutting surface for cutting devices of this character. The preferred embodiment of the present invention, which will be subsequently described in detail, takes the form of a grooved lapping disk supported for rotation and having a downwardly depending skirt. A motor having a rotational output parallel to the axis of the lapping disk carries a resilient wheel which drivingly engages the peripheral skirt of the lapping disk to provide a friction type drive. A guide arm is connected through a bell crank type mechanism to the rotating lapping wheel in a fashion to produce a reciprocating pivotal motion of the guide arm. A self-aligning head is carried at the free end of the guide arm and traverses the working surface of the lapping disk. The self-aligning head cooperates with a blade holder to provide an improved finish over the blade surface by insuring an even pressure over the entire blade surface against the working surface of the lapping disk. The friction clutch engaging the output of the motor to the lapping disk insures that an excessive pressure applied to the lapping disk will not produce an overloaded condition on the driving motor.

Still another advantage of the present invention is that the entire apparatus is constructed in such a fashion that it can be supported and transported in a hand carried case.

It is therefore an object of the present invention to provide apparatus for automatically refinishing the blade sections of barber clippers and the like by providing a self-aligning clipper blade holder adapted to apply an even pressure on the blade section against a rotating lapping disk and including means for traversing the blade holder across the abrasive surface of the lapping disk.

It is another object of the present invention to improve the durability of blade sharpening apparatus having a motor drivingly connected to a rotating lapping disk by providing the disk with a peripheral skirt section and the output shaft of the motor with a resilient rotating member for frictionally engaging the peripheral skirt to impart rotational movement to the disk.

Still another object of the present invention is to improve the utility of blade sharpening apparatus by providing such apparatus mounted in a hand carried case for easy transport.

Still other objects and advantages of the present invention will readily occur to one skilled in the art to which the invention pertains upon reference to the following detailed description of the preferred embodiment of the invention. The description makes reference to the accompanying drawings in which like reference characters refer to like parts throughout the several views and in which:

FIG. 1 is a perspective view of a portable blade sharpening apparatus illustrating a preferred embodiment of the present invention;

FIG. 2 is a perspective exploded view of the blade holder illustrated in FIG. 1;

FIG. 3 is a view of the underside of the mounting panel of the blade sharpening apparatus illustrating the crank linkage between the rotating disk and the reciprocating guide arm post;

FIG. 4 is an elevational view of the linkage illustrated in FIG. 3;

FIG. 5 is a longitudinal sectional view through the blade holder and showing the blade in sharpening engagement with the working surface of the rotating disk; and

FIG. 6 is a sectional view taken along line 66 of FIG. 5,

DESCRIPTION Now referring to the drawings FIG. 1 illustrates a preferred blade sharpening apparatus comprising a generally rectangular casing section 10 defining a compartment 11 and a cover section 12 joined for pivotal movement by hinges 14. The cover section 12 and the casing section 10 are hinged for cooperative movement between a first closed condition wherein the compartment 11 is closed and a second opened condition wherein access is permitted to the compartment 11. The cover section 12 is secured to the casing section 10 by a pair of cooperating locking sections 16 and 18. A handle member 20 is fixed to the casing section 10 and provides means for transporting the blade sharpening apparatus. The casing section 10 and cover section 12 are preferably formed of a lightweight, durable plastic material.

Now referring to FIGS. 1 and 4, a mounting panel member 22 is supported by the side walls of the casing section 10. As can best the seen in FIG. 4, a mounting block 24 is carried on the underside of the panel member 22 and supports a bearing member 26 which is turn supports for rotation a spindle 28. The upper end of the spindle 28 carries a lapping disk 30 for rotation The lapping disk 30 has a flat working surface 32, including a plurality of shallow circular grooves 34. The disk 30 is preferably circular and has a downward depending peripheral skirt 36. The disk 30 is preferably formed of a lightweight material such as an aluminum alloy. A fractional horsepower motor 38 is fixed to the underside of the mounting member 22 and has an upward extending output shaft 40 which carries a resilient wheel member 42. The motor 38 is disposed such that the circumference of the wheel member 42 engages the inner surface of the skirt 36 so that rotation of the output shaft 40 is transmitted through the wheel member 42 to the skirt 36. The wheel 42 thus provides a frictional driving engagement with the disk 30 and is preferably formed of a rubber-like compound. On-olf operation of the motor 38 is controlled by a circuit closing switch 43 (FIG. 3) mounted on the underside of the mounting member 22 and has an actuating element extending to the upper surface of the mounting member 22.

A sheave 44 is carried by the lower end of the spindle 28 and is connected by a rubber belt 46 to a second larger sheave 48. A mounting block 50 having a bearing provided therein (not shown) carries a shaft 52 which supports the sheave 48 for rotation.

The sheave 48 carries a downward depending pin 54 which is rotatably connected to one end of a link 56, the opposite end of which is connected to a bent pin 58. The bent pin 58 has an end fixed to the lower end of a vertical shaft 60 which is supported by a bearing block 62. The vertical shaft 60 has an upper end extending above the disk 30. Now inspection of FIG. 3 will indicate that rotation of the sheave 48 will cause the shaft 64 to oscillat in an arc defined by the relative lengths of the link 56 and the bent pin 58.

Now referring to FIGS. 1, 2 and a block 66 is carried at the extreme end of the shaft section 64. A rod 68 is loosely journaled about a horizontal axis in the block 66 and has a free end biased downwardly toward the working surface 32 of the lapping disk 30 by a spring member 70 fixed to the extreme end of the rod 68. The spring 70 reacts against a screw 72 carried by the block 66. The free end of the rod 68 is threaded at 74 and engaged to a leg 76 of a head generally indicated at 78. It is to be understood that the leg 76 is loosely engaged with the threaded section 74. The rod 68 is further provided with a right angle bend 80 between the block 66 and the leg 76, Thus, it can be seen that the head 78 is rotatable relative to the working surface 32 of the lapping disk 30 about two mutually perpendicular axes associated with the rod 68.

The head 78 is further provided with a pair of oppositely directed wing sections 82. Each of the wings 82 is provided with a downwardly depending dowel element 88 which projects away from the under surface of the head 78 a distance greater than the pivot pin 86 and is spaced from the pin 86 as can best be seen in FIG. 6.

Now as can best be seen in FIGS. 2 and 6, an adaptor element 90 has a pair of bores 92 associated with the dowels 88. Preferably the bores 92 loosely fit the dowels 88. The adaptor 90 further has a recess 94 associated with the pivot pin 86 and which has a depth less than the extending pointed end of the pivot pin 86. It can therefore be seen that the adaptor 90 when engaged with the head 78 is free for a slight pivotal movement relative to the wings 82 of the head 78. Rotation of the adaptor 90 relative to the head 78 is prevented by the dowels 88 fitting in the bores 92.

The downward facing surface of the adaptor 90 is adapted to accommodate a clipper blade 96. For purposes of description, the clipper blade 96 has a pair of spaced apart apertures 98 in which engage a pair of downwardly depending pins 100 carried by the adaptor 90. The apertures 98 of the clipper section 96 normally are Provided as means for securing the clipper section to the main body of the clipper and for this reason are normally spaced apart at a distance dictated by the manufacturer of the particular clipper. Therefore the adaptor pins 100 are spaced apart to correspond to the aperures 98. For this reason there is normally an adaptor associated with each of the different types of clipper blade sections. The clipper blade section 96 is illustrated as having a pair of sliding surfaces 102 and 104 which are to be finished and which slidingly mate with a corresponding surface carried on a companion clipper blade section. Thus, as it can best be seen in FIG. 5, the surfaces 102 and 104 abut the working surface 32 of the lapping disk 30.

In operation, a suspension of a conventional abrasive powder in a liquid is distributed over the working surface 32 of the disk. The purpose of the grooves 34 is to remove debris from the working surface of the disk and to remove excess abrasive powder. Normally, the abrasive powder is useful until the liquid vehicle in which it is suspended has dried.

The blade section 96 is combined with the head 78 and the adaptor 90, such that the surfaces 102 and 104 to the blade section are urged downwardly against the working surface 32 of the disk and the motor 38 energized to rotate the disk about its axis. As the disk rotates, the aforementioned linkage causes the shaft 64 to oscillate in a predetermined are thus causing the head 78 to carry the blade section 96 in a traversing relationship across the working face 32 of the disk 30. As the blade section 96 traverses the working surface 32 of the rotating disk, the surfaces 102 and 104 are evenly abraded to produce a finished, polished surface. The operation is continued until the abrasive suspension has dried. The surfaces 102 and 104 are then inspected to see that they are evenly ground and if not, the operation is repeated until they are in satisfactory condition. Normally the number of times the operation has to be repeated is dependent on the condition of the surfaces 102 and 104.

It can therefore be seen that I have described in detail a portable blade sharpening apparatus having a blade holder supported for self alignment so that the blade section 96 is evenly biased against the working surface of the lapping disk 30. The improved blade shape sharpening apparatus is also provided with a frictional driving engagement to insure that an excessive load imposed on the disk will not be transmitted to the driving motor.

It is to be understood that although I have described but one preferred embodiment of my invention, that many modifications and variations may be made therein without departing from the spirit of the invention as expressed in the scope of the accompanying claims.

Having described my invention, I claim.

1. Lapping apparatus useful in finishing the sliding surfaces of barber clipper blade sections and the like, said apparatus comprising:

a disk having a flat working surface and a downwardly depending peripheral skirt portion,

means for rotating said disk including a resilient wheel member in engagement with said skirt portion,

an arm member supported adjacent said disk for pivotal movement about two mutually perpendicular axes, with one of said axes parallel to the axis of rotation of said disk whereby said arm member is movable across the working surface of said disk, and a holder for said blade section caried at the free end of said arm member,

said free end of said arm member being provided with a portion having a pair of pin elements and a pointed pressure element disposed intermediate and less in length than said pin elements, said holder being adapted to carry a blade section and having a pair of spaced apart apertures for loosely receiving said pin elements, and a recess disposed intermediate said apertures for receiving said pressure element, said pressure element having a length more than the depth of said recess whereby said holder is spaced from said arm member and is free to move slightly about said pressure element,

means urging said arm member about the pivotal axis perpendicular to the axis of rotation of said disk and toward said disk so that the surface of said blade is urged into abutment with the working surface of said disk with an even pressure, and

means drivingly connecting said arm member and said disk rotating means to move said arm member recip- 5 6 rocally about the pivotal axis of said arm member circular shallow grooves formed about the axis of rotathat is parallel to the rotational axis of said disk to tion of said disk. produce a traversing movement of said arm member 5. The invention as defined in claim 1, wherein said relative to the working face of said disk. apparatus is mounted in a hand carried case comprising 2. The apparatus as defined in claim 1 and including a pair of casing sections cooperative closeable to define a support member supported for rotation about an 0 a compartment for said apparatus and operable to permit axis parallel to the axis of rotation of said disk, access to said apparatus. said arm member being carried by said support member for rotation therewith and for pivoting with re- Refere e Cit d spect thereto about an axis perpendicular to the axis of rotation of said support member, and 10 UNITED STA TES PATENTS said urging means comprising spring bias means carried 3,128,530 4/ 1964 DaVlS 51234 X by said support member for urging pivotal movement 3,210,393 10/1965 Jackson 51170 of said arm member with respect to said support member in a direction toward the working face of 15 FOREIGN PATENTS said disk, 578,110 6/1924 France. 3. The apparatus as defined in claim 1 and including 8 /1893 G eat Britain. a shaft supporting said disk for rotation, and 13,939 90 at Britain. said last mentioned means comprises a link connecting 433,766 948 Italy.

said shaft and said arm member to produce recip- 20 procating movement of said arm member upon ro- HAROLD WHITEHEAD, Primary Exammertation of said shaft. 4. The invention as defined in claim 1, wherein the 1 working face of said disk is provided with a plurality of 5 124 

